/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#include "cbtCollisionDispatcher.h"
#include "LinearMath/cbtQuickprof.h"

#include "BulletCollision/BroadphaseCollision/cbtCollisionAlgorithm.h"

#include "BulletCollision/CollisionShapes/cbtCollisionShape.h"
#include "BulletCollision/CollisionDispatch/cbtCollisionObject.h"
#include "BulletCollision/BroadphaseCollision/cbtOverlappingPairCache.h"
#include "LinearMath/cbtPoolAllocator.h"
#include "BulletCollision/CollisionDispatch/cbtCollisionConfiguration.h"
#include "BulletCollision/CollisionDispatch/cbtCollisionObjectWrapper.h"

#ifdef BT_DEBUG
#include <stdio.h>
#endif

cbtCollisionDispatcher::cbtCollisionDispatcher(cbtCollisionConfiguration* collisionConfiguration) : m_dispatcherFlags(cbtCollisionDispatcher::CD_USE_RELATIVE_CONTACT_BREAKING_THRESHOLD),
																								 m_collisionConfiguration(collisionConfiguration)
{
	int i;

	setNearCallback(defaultNearCallback);

	m_collisionAlgorithmPoolAllocator = collisionConfiguration->getCollisionAlgorithmPool();

	m_persistentManifoldPoolAllocator = collisionConfiguration->getPersistentManifoldPool();

	for (i = 0; i < MAX_BROADPHASE_COLLISION_TYPES; i++)
	{
		for (int j = 0; j < MAX_BROADPHASE_COLLISION_TYPES; j++)
		{
			m_doubleDispatchContactPoints[i][j] = m_collisionConfiguration->getCollisionAlgorithmCreateFunc(i, j);
			cbtAssert(m_doubleDispatchContactPoints[i][j]);
			m_doubleDispatchClosestPoints[i][j] = m_collisionConfiguration->getClosestPointsAlgorithmCreateFunc(i, j);
		}
	}
}

void cbtCollisionDispatcher::registerCollisionCreateFunc(int proxyType0, int proxyType1, cbtCollisionAlgorithmCreateFunc* createFunc)
{
	m_doubleDispatchContactPoints[proxyType0][proxyType1] = createFunc;
}

void cbtCollisionDispatcher::registerClosestPointsCreateFunc(int proxyType0, int proxyType1, cbtCollisionAlgorithmCreateFunc* createFunc)
{
	m_doubleDispatchClosestPoints[proxyType0][proxyType1] = createFunc;
}

cbtCollisionDispatcher::~cbtCollisionDispatcher()
{
}

cbtPersistentManifold* cbtCollisionDispatcher::getNewManifold(const cbtCollisionObject* body0, const cbtCollisionObject* body1)
{
	//cbtAssert(gNumManifold < 65535);

	//optional relative contact breaking threshold, turned on by default (use setDispatcherFlags to switch off feature for improved performance)

	cbtScalar contactBreakingThreshold = (m_dispatcherFlags & cbtCollisionDispatcher::CD_USE_RELATIVE_CONTACT_BREAKING_THRESHOLD) ? cbtMin(body0->getCollisionShape()->getContactBreakingThreshold(gContactBreakingThreshold), body1->getCollisionShape()->getContactBreakingThreshold(gContactBreakingThreshold))
																																: gContactBreakingThreshold;

	cbtScalar contactProcessingThreshold = cbtMin(body0->getContactProcessingThreshold(), body1->getContactProcessingThreshold());

	void* mem = m_persistentManifoldPoolAllocator->allocate(sizeof(cbtPersistentManifold));
	if (NULL == mem)
	{
		//we got a pool memory overflow, by default we fallback to dynamically allocate memory. If we require a contiguous contact pool then assert.
		if ((m_dispatcherFlags & CD_DISABLE_CONTACTPOOL_DYNAMIC_ALLOCATION) == 0)
		{
			mem = cbtAlignedAlloc(sizeof(cbtPersistentManifold), 16);
		}
		else
		{
			cbtAssert(0);
			//make sure to increase the m_defaultMaxPersistentManifoldPoolSize in the cbtDefaultCollisionConstructionInfo/cbtDefaultCollisionConfiguration
			return 0;
		}
	}
	cbtPersistentManifold* manifold = new (mem) cbtPersistentManifold(body0, body1, 0, contactBreakingThreshold, contactProcessingThreshold);
	manifold->m_index1a = m_manifoldsPtr.size();
	m_manifoldsPtr.push_back(manifold);

	return manifold;
}

void cbtCollisionDispatcher::clearManifold(cbtPersistentManifold* manifold)
{
	manifold->clearManifold();
}

void cbtCollisionDispatcher::releaseManifold(cbtPersistentManifold* manifold)
{
	//printf("releaseManifold: gNumManifold %d\n",gNumManifold);
	clearManifold(manifold);

	int findIndex = manifold->m_index1a;
	cbtAssert(findIndex < m_manifoldsPtr.size());
	m_manifoldsPtr.swap(findIndex, m_manifoldsPtr.size() - 1);
	m_manifoldsPtr[findIndex]->m_index1a = findIndex;
	m_manifoldsPtr.pop_back();

	manifold->~cbtPersistentManifold();
	if (m_persistentManifoldPoolAllocator->validPtr(manifold))
	{
		m_persistentManifoldPoolAllocator->freeMemory(manifold);
	}
	else
	{
		cbtAlignedFree(manifold);
	}
}

cbtCollisionAlgorithm* cbtCollisionDispatcher::findAlgorithm(const cbtCollisionObjectWrapper* body0Wrap, const cbtCollisionObjectWrapper* body1Wrap, cbtPersistentManifold* sharedManifold, ecbtDispatcherQueryType algoType)
{
	cbtCollisionAlgorithmConstructionInfo ci;

	ci.m_dispatcher1 = this;
	ci.m_manifold = sharedManifold;
	cbtCollisionAlgorithm* algo = 0;
	if (algoType == BT_CONTACT_POINT_ALGORITHMS)
	{
		algo = m_doubleDispatchContactPoints[body0Wrap->getCollisionShape()->getShapeType()][body1Wrap->getCollisionShape()->getShapeType()]->CreateCollisionAlgorithm(ci, body0Wrap, body1Wrap);
	}
	else
	{
		algo = m_doubleDispatchClosestPoints[body0Wrap->getCollisionShape()->getShapeType()][body1Wrap->getCollisionShape()->getShapeType()]->CreateCollisionAlgorithm(ci, body0Wrap, body1Wrap);
	}

	return algo;
}

bool cbtCollisionDispatcher::needsResponse(const cbtCollisionObject* body0, const cbtCollisionObject* body1)
{
	//here you can do filtering
	bool hasResponse =
		(body0->hasContactResponse() && body1->hasContactResponse());
	//no response between two static/kinematic bodies:
	hasResponse = hasResponse &&
				  ((!body0->isStaticOrKinematicObject()) || (!body1->isStaticOrKinematicObject()));
	return hasResponse;
}

bool cbtCollisionDispatcher::needsCollision(const cbtCollisionObject* body0, const cbtCollisionObject* body1)
{
	cbtAssert(body0);
	cbtAssert(body1);

	bool needsCollision = true;

#ifdef BT_DEBUG
	if (!(m_dispatcherFlags & cbtCollisionDispatcher::CD_STATIC_STATIC_REPORTED))
	{
		//broadphase filtering already deals with this
		if (body0->isStaticOrKinematicObject() && body1->isStaticOrKinematicObject())
		{
			m_dispatcherFlags |= cbtCollisionDispatcher::CD_STATIC_STATIC_REPORTED;
			printf("warning cbtCollisionDispatcher::needsCollision: static-static collision!\n");
		}
	}
#endif  //BT_DEBUG

	if ((!body0->isActive()) && (!body1->isActive()))
		needsCollision = false;
	else if ((!body0->checkCollideWith(body1)) || (!body1->checkCollideWith(body0)))
		needsCollision = false;

	return needsCollision;
}

///interface for iterating all overlapping collision pairs, no matter how those pairs are stored (array, set, map etc)
///this is useful for the collision dispatcher.
class cbtCollisionPairCallback : public cbtOverlapCallback
{
	const cbtDispatcherInfo& m_dispatchInfo;
	cbtCollisionDispatcher* m_dispatcher;

public:
	cbtCollisionPairCallback(const cbtDispatcherInfo& dispatchInfo, cbtCollisionDispatcher* dispatcher)
		: m_dispatchInfo(dispatchInfo),
		  m_dispatcher(dispatcher)
	{
	}

	/*cbtCollisionPairCallback& operator=(cbtCollisionPairCallback& other)
	{
		m_dispatchInfo = other.m_dispatchInfo;
		m_dispatcher = other.m_dispatcher;
		return *this;
	}
	*/

	virtual ~cbtCollisionPairCallback() {}

	virtual bool processOverlap(cbtBroadphasePair& pair)
	{
		(*m_dispatcher->getNearCallback())(pair, *m_dispatcher, m_dispatchInfo);
		return false;
	}
};

void cbtCollisionDispatcher::dispatchAllCollisionPairs(cbtOverlappingPairCache* pairCache, const cbtDispatcherInfo& dispatchInfo, cbtDispatcher* dispatcher)
{
	//m_blockedForChanges = true;

	cbtCollisionPairCallback collisionCallback(dispatchInfo, this);

	{
		BT_PROFILE("processAllOverlappingPairs");
		pairCache->processAllOverlappingPairs(&collisionCallback, dispatcher, dispatchInfo);
	}

	//m_blockedForChanges = false;
}

//by default, Bullet will use this near callback
void cbtCollisionDispatcher::defaultNearCallback(cbtBroadphasePair& collisionPair, cbtCollisionDispatcher& dispatcher, const cbtDispatcherInfo& dispatchInfo)
{
	cbtCollisionObject* colObj0 = (cbtCollisionObject*)collisionPair.m_pProxy0->m_clientObject;
	cbtCollisionObject* colObj1 = (cbtCollisionObject*)collisionPair.m_pProxy1->m_clientObject;

	if (dispatcher.needsCollision(colObj0, colObj1))
	{
		cbtCollisionObjectWrapper obj0Wrap(0, colObj0->getCollisionShape(), colObj0, colObj0->getWorldTransform(), -1, -1);
		cbtCollisionObjectWrapper obj1Wrap(0, colObj1->getCollisionShape(), colObj1, colObj1->getWorldTransform(), -1, -1);

		//dispatcher will keep algorithms persistent in the collision pair
		if (!collisionPair.m_algorithm)
		{
			collisionPair.m_algorithm = dispatcher.findAlgorithm(&obj0Wrap, &obj1Wrap, 0, BT_CONTACT_POINT_ALGORITHMS);
		}

		if (collisionPair.m_algorithm)
		{
			cbtManifoldResult contactPointResult(&obj0Wrap, &obj1Wrap);

			if (dispatchInfo.m_dispatchFunc == cbtDispatcherInfo::DISPATCH_DISCRETE)
			{
				//discrete collision detection query

				collisionPair.m_algorithm->processCollision(&obj0Wrap, &obj1Wrap, dispatchInfo, &contactPointResult);
			}
			else
			{
				//continuous collision detection query, time of impact (toi)
				cbtScalar toi = collisionPair.m_algorithm->calculateTimeOfImpact(colObj0, colObj1, dispatchInfo, &contactPointResult);
				if (dispatchInfo.m_timeOfImpact > toi)
					dispatchInfo.m_timeOfImpact = toi;
			}
		}
	}
}

void* cbtCollisionDispatcher::allocateCollisionAlgorithm(int size)
{
	void* mem = m_collisionAlgorithmPoolAllocator->allocate(size);
	if (NULL == mem)
	{
		//warn user for overflow?
		return cbtAlignedAlloc(static_cast<size_t>(size), 16);
	}
	return mem;
}

void cbtCollisionDispatcher::freeCollisionAlgorithm(void* ptr)
{
	if (m_collisionAlgorithmPoolAllocator->validPtr(ptr))
	{
		m_collisionAlgorithmPoolAllocator->freeMemory(ptr);
	}
	else
	{
		cbtAlignedFree(ptr);
	}
}
